The embodiments disclosed within this specification relate to validation of a schema that itself is used to validate one or more document instances.
The use of XML messages to relay information, especially via Internet based protocols, is prevalent. Essentially, an XML message is an XML document communicated via a suitable communication medium. With the proliferation of XML, and the increased complexity Internet communications, XML messages also are becoming increasingly complex.
XML schema oftentimes are used to specify the content of XML documents. An XML schema is a description of a type of XML document, typically expressed in terms of constraints on the structure and content of documents of that type, above and beyond the basic syntactical constraints imposed by XML itself. In illustration, XML schema generally are expressed using some combination of grammatical rules governing the order of elements, Boolean predicates that the content must satisfy, data types governing the content of elements and attributes, etc.